[tex]\it a)\ \ \sqrt{17}>\sqrt{16} \Rightarrow \sqrt{17}>4 \Rightarrow \sqrt{17}-4>0\\ \\ b)\ \ \sqrt{47}<\sqrt{49} \Rightarrow \sqrty{47}<7 \Rightarrow -7+\sqrt{47}<0\\ \\ c)\ \dfrac{8}{9}<1<\sqrt{1,25} \Rightarrow \dfrac{8}{9}-\sqrt{1,25}<0\\ \\ d)\ \sqrt{10}<\sqrt{20} \Rightarrow \sqrt{10}<2\sqrt5 \Rightarrow \sqrt{10}-2\sqrt5<0[/tex]
